No, that TH per $ amount is pretty terrible I think.  I'd probably be better off just sticking with a Avalon Nano 3...  If they can release a 12TH/s miner for less than a thousand dollars, then I might be interested.  We're talking solo mining here though, so it is most likely a complete loss.  Overpaying for the hardware makes it worse.  Sure, the Avalon might fall apart, but how long would you have to run a Bitaxe to make up for the higher price per TH?  My guess is years and with summer not far away, I think it might make sense for me in my personal position to let the Avalon do it's thing for a couple more months and then just turn it off until next winter.  If Bitcoin bubbles up then maybe it would be worth trying to grab some hardware at the top for next winter.